Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,587   Posts: 1,545,834   Online: 1122
      
Page 4 of 4 FirstFirst 1234
Results 31 to 32 of 32
  1. #31

    Join Date
    Mar 2009
    Location
    NC
    Shooter
    Medium Format
    Posts
    81
    Quote Originally Posted by Kirk Keyes View Post
    I've built one and added a stepper motor to it to automate the turning of screw. They work well for exposures up to about 10 minutes or so and you need to be very careful aligning them to north otherwise you will get drift in the stars.

    Kirk,
    Not entirely true, if you build a double arm tracker you can get exposure of over an hour long. The key is in the design. I am in the process of building one now (should be finished tomorrow once I get home from work) and based on my dimensions mine should track with exceptional results up to the first 30 mins then average results up to 60 mins and then there after exceptional results. The key is getting it to track at 15.04 degrees per min.

    But you are right polar alignment is crucial.


    If you want to build one, this is a great start http://www.davetrott.com/DoubleArmBarnDoor.html

    ~mike

  2. #32

    Join Date
    Jun 2004
    Location
    Portland, OR
    Shooter
    4x5 Format
    Posts
    3,268
    Mike - make sure you post some photos! They are fun devices and easy to make.
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

Page 4 of 4 FirstFirst 1234


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin